Among semiconductor devices utilizing a power semiconductor element, there exists a semiconductor device provided with a current sensing cell that obtains a current for a current-detection by splitting a current flowing in the power semiconductor element, in order to detect a current so as to protect the power semiconductor element when an overcurrent flows therein. An overcurrent protector for a transistor utilizing a current flowing in the current sensing cell include an overcurrent protector for a transistor in which a current detection means formed of a resistor receives a current from a current-detection transistor (a current sensing cell) and inputs the current to a comparator, so that a current is detected (e.g., Patent Document 1).
In addition, overcurrent detection circuits include the one in which current detection is performed in such a way that a current-detection source (the output of a current sensing cell) is connected to the inverting input terminal of an operational amplifier in a current/voltage conversion circuit configured with the operational amplifier and a current detection resistor (e.g., Patent Document 2).